JPS5814487B2 - Soaking control method for rolled material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling the soaking of a bar-shaped rolled material, and particularly to a control method suitable for use in a pipe manufacturing process.

The progress in rolling technology in recent years, coupled with the introduction of computers, has been remarkable.

In plate rolling, the introduction of thickness-changing rolling, completely continuous rolling, etc. has become a reality, and there is a tendency for almost complete automation to be realized.

However, automation has not yet been achieved in tube rolling, which plays an equally important role in rolling as plate rolling, and production still continues to rely on the experience and intuition of experts.

The reason why automation has not been achieved in rolling steel pipes, etc. is as follows.
This is thought to be because the rolling process is more complicated than that of steel sheets, and as a result, there are many parts that have not yet been fully analyzed theoretically.

Recently, automation using computers has begun to be considered in the pipe manufacturing process, and although calculations for rolling mill setups have been realized in a small number of cases, other complex operations still rely on skilled workers. be.

In this pipe-making process, it is said that the so-called perforation process, in which the material is pierced into the pipe, requires the experience and intuition of experts to the greatest extent.

In this drilling, the problem is the variation in deformation resistance of each part of the material due to uneven temperature distribution of the material.

If the deformation resistance is not the same in each part of the material, a so-called uneven wall pipe, in which the wall thickness of the pipe is not uniform, will be created during drilling.

This uneven thickness that occurs during the drilling stage has a negative effect on the subsequent steps, and its correction leads to a decrease in productivity and a decrease in quality.

Therefore, in the drilling work, emphasis is placed on empirical know-how such as selection of appropriate tools, rolling speed (drilling speed), roll opening degree, etc.

However, what is important here is that uneven wall thickness pipes are caused by variations in the temperature distribution of the material.

No matter how highly skilled the person is, if there are variations in the temperature of the materials that are the cause, their skills will not be able to be fully demonstrated, and it will be difficult to prevent uneven wall thickness pipes from occurring. Naturally, there are limits.

For this reason, conventionally, when pipes with uneven wall thickness occur, the first step is to readjust the roll opening of the rolling mill for perforation, or replace the piercer for perforation, and then proceed to the next step. Performs perforation of rolled material.

If the uneven wall thickness of the pipe still occurs,
This time, they had to repeat the process of changing the control settings of the furnace that supplies the rolled material and adjusting the soaking time.

The problem with this conventional technology is that the roll opening degree and rolling speed of the rolling mill are readjusted only after the phenomenon of uneven wall thickness pipes occurs (this method prevents uneven wall thickness pipes from occurring). Furthermore, since these adjustments are made ignoring the true cause of uneven wall thickness pipes, they do not provide an essential solution and naturally have limitations.

In addition, due to the repeated occurrence of pipes with uneven thickness, the soaking time of the rolled material in the furnace is adjusted, but although this is recognized to have some preventive effect against the occurrence of pipes with uneven thickness in the future, in reality it is Because the variation in temperature of the rolled material, which is the main cause of meat formation, is not measured, it is not possible to provide an appropriate soaking time.

As a result, whether pipes with uneven thickness do not occur or not is determined by the fact that the soaking time of the furnace is adjusted by the occurrence of the pipe with uneven thickness, and the rolled material in the furnace that has been soaked during that soaking time is transferred to the rolling mill. This poses a problem in that it cannot be determined without seeing the results of the supplied and perforated holes.

If uneven wall thickness pipes occur again, the soaking time is reset and the situation is monitored, so any rolled material extracted from the furnace during that time has the possibility of being perforated by the uneven wall pipes. .

In the present invention, based on the recognition that the variation in deformation resistance, which is a factor in the occurrence of uneven wall thickness pipes, is mostly caused by variation in temperature at each part of the rolled material, we have developed a method for reducing this temperature variation, that is, the uniform heating state of the rolled material. Focus on.

By understanding this uniform heating state, it is not only possible to almost completely predict the occurrence of pipes with uneven thickness in the pipe manufacturing process, but also it is possible to realize uniform heating control of the rolled material using the uniform heating state.

Therefore, an object of the present invention is to detect the soaking state of a rolled material,
It is an object of the present invention to provide a method for controlling uniform heating.

The present invention measures the temperature at a plurality of points in the circumferential direction of a rolled material, uses the measured values to detect a soaked state, and uses the measured values of the soaked state to determine the temperature of the rolled material using a furnace or other heat soaking adjustment means. It is distinctive in that it controls.

Other objects and features of the invention will become apparent from the description below.

Hereinafter, the present invention will be explained in detail using the drawings.

First, the principle of the present invention will be explained.

The rolled material is charged into a furnace, extracted from the furnace through a heating process and a soaking process, and then supplied to a rolling mill for perforation as shown in FIG. 1, for example.

In FIG. 1, 1 is a piercer roll, 2 is a piercer, and 3 is a rolled material.

The rolled material extracted from the furnace (not shown) advances to the roll exit side while being rotated by the piercer roll 1.
The hole is pierced by piercer 2.

As mentioned above, a pipe with uneven wall thickness occurs during such a drilling process.

The cause of this uneven wall thickness pipe is closely related to the soaking state of the rolled material.

To explain in more detail, the causes of uneven wall thickness pipes are:
This is probably due to variations in the deformation resistance of each part of the rolled material, but as is clear from the properties of metals, this deformation resistance is most affected by the temperature of the rolled material.

The present invention pays attention to this point and utilizes the temperature distribution of each part of the rolled material, that is, the uniform heating state, as a causal parameter for the occurrence of uneven wall pipes.

The soaking state can be recognized by measuring the temperature of each part of the rolled material and by the degree of variation.

Specifically, this is to determine in which frame the difference temperature ΔTM (°C) between the highest and lowest temperature values of each part falls within a frame divided into several stages in advance. This can be recognized as such, or the temperature difference ΔTM can be used as it is as the degree of uniform heating.

Alternatively, all measured values may be averaged and the difference between the average value and each measured value may be used, or the difference may be recognized as the degree of dispersion.

In short, the uniform heating state can be recognized by detecting the temperature at multiple points on the rolled material and comparing them in some way.

However, what is important here is that it is not enough to simply measure the temperature at multiple points on the rolled material.

It should be noted that uneven wall thickness pipes often occur when the temperature in the cross section of the rolled material to be drilled is not uniform.

Even if the degree of uniformity in the longitudinal direction of the rolled material is poor, if the uniform heating condition in the circumferential direction is good, uneven wall thickness of the pipe will hardly occur.

Therefore, even if the soaking state is detected in the longitudinal direction of the rolled material, the occurrence of uneven thickness cannot be accurately predicted.

Therefore, in the present invention, the temperature is measured not in the longitudinal direction of the rolled material but in the circumferential direction at complementary points, and the soaking state is detected using this measured value.

Of course, it goes without saying that if you repeat temperature measurements at multiple positions in the circumferential direction of the rolled material multiple times in the longitudinal direction of the rolled material, it is possible to detect a uniform heating state that is useful for predicting the occurrence of uneven wall thickness pipes. stomach.

This is because there are generally variations in temperature both in the circumferential direction and in the longitudinal direction of a rolled material, and when detecting a uniformly heated state in the circumferential direction for a certain part in the longitudinal direction, and when detecting a uniformly heated state in the circumferential direction for other parts. This is because there are many differences between the two cases.

Therefore, it is better to repeat the soaking state detection in the circumferential direction several times in the longitudinal direction of the rolled material and make a comprehensive judgment.

Next, a method for detecting a soaking state will be specifically described.

FIG. 2 is a drawing showing a specific example of detecting a soaking state.

In the figure, 41 to 47 are rollers for transporting the rolled material 3.

5L52, 53, 54.55...5n (not shown) indicates a temperature detector that detects temperatures at multiple locations in the circumferential direction of the rolled material 3.

6 is a calculator, 61 is a process input/output device that takes in the amount of pressure (in this case, the temperature T1 to Tn of each part in the circumferential direction of the rolled material) and outputs control data for the process, and 62 is a process input/output device. A central processing unit 63 performs calculations (in this case, detecting the soaking state) using the process quantities etc. from 61, and 63 has a built-in storage device for storing programs, process quantities, calculation results, etc.

7 is a data input section for supplying necessary programs, data, etc. to the computer 6 in advance.

Reference numeral 8 denotes a display unit such as a display device that allows the operator to recognize the calculation result (in this case, the soaking state) calculated by the calculator 6.

In such a configuration, when the rolled material 3 extracted from the furnace reaches the installation position of the temperature detectors 51 to 5n, the output of each temperature detector increases rapidly.

By monitoring this sudden change, the computer 6 can detect that the rolled material 3 has reached the temperature detector installation position.

Note that this detection can also be performed by providing an appropriate detection means, such as a hot metal detector or a limit switch, near the installation position of the temperature detector.

By detecting the rolled material 3, the central processing unit 62 in the computer 6
stores T1 to Tn, which are the outputs of the temperature detectors 5-1 and 5-n, in the storage device 63 via the input/output device 61.

Then, the central processing unit 62 calculates the soaking state using the stored values T1 to Tn according to a program that is input in advance from the data input unit 7 and stored in the storage device 63.

This calculation result is output to the display section 8 and is also stored in a predetermined area within the storage device 63.

Detection of the soaking state for one rolled material 3 is performed by
If this is repeated multiple times in the length direction, a more accurate soaking state can be recognized. Therefore, for example, the soaking state can be detected at the tip, center, and rear end of the rolled material and displayed on the display means 8, respectively. Or, only the worst soaking condition is performed, or the average heating condition is displayed.

These displays can be freely selected depending on the situation and usage.

Regarding the detection of the soaking state shown in FIG. 2, a specific flowchart for detecting the soaking state is shown in FIG.

By storing a program according to such a flowchart in the storage device 63 of the calculator 6, it is possible to detect the soaking state.

In FIG. 3, as is clear from the flow, temperatures T1 to Tn in the circumferential direction of the rolled material are taken (steps FO to Tn).
Steps up to F2), select the highest value TMAX and lowest value MIN from them (steps F3 to F9), and detect the soaking state based on the difference ΔTM between them (steps F10 to F1).
Steps up to 2)

Here, in step Fll, specifically, for example, a table as shown in Table 1 is prepared in the storage device 63,
The soaking state is calculated by referring to this table.

In addition, in order to control the process amount (for example, the time in the furnace, etc.) using this soaking state, we have obtained the result that it is possible to control the process amount (for example, the time in the furnace, etc.) with more accuracy by using ΔTM as it is.

Using the calculation result of ΔTM, in step F11, it is selected which level (index, state, necessity of control) this ΔTM is at.

The results are then output to the display unit 8 as shown in step 12.

Therefore, the operator can check the current state of uniform heat and can realize appropriate operation.

Detection of the soaked state is not limited to the method shown in FIG. 3, but the most suitable detection method should be adopted depending on the type and characteristics of the target process.

Next, another method of detecting a soaking state will be explained. FIG. 4 is a drawing showing another specific example.

In the figure, the same numbers as in FIG. 2 indicate the same parts.

5 is a thermometer installed near the rolling mill.

This rolling mill is a Mannesmann type perforation machine, and this type of rolling mill performs perforation while rotating the rolled material 3 with the roll 1.

Therefore, even if a plurality of temperature detectors (for example, 5-1 to 5-n in FIG. 2) are not provided in the circumferential direction of the rolled material 3, if one temperature sensor 5 is provided, the circumferential direction of the rolled material 3 can be adjusted. It is possible to recognize the temperature distribution in the direction.

This recognition is possible because the temperature is detected in a spiral manner as the rolled material 3 moves forward while rotating, so it cannot be said that the temperature is perfectly measured in the circumferential direction of the rolled material 3, but it is uniform in the circumferential direction of the rolled material to the extent that there is no problem in practical use. Thermal conditions can be detected.

That is, as shown in FIG. 5, the temperature detector 5 measures the temperature of the portion of the rolled material 3 marked with an "X" as the rolled material 3 rotates in eight directions.

To measure the temperature in the circumferential direction of the rolled material, we measured the temperature multiple times as shown in Figures a and b, rather than measuring once for each rolled material, and detected the uniform heating state for these measurements. As in the previous example, this method yields more useful results.

The specific detection method for the embodiment shown in FIG. 4 will be explained as follows.

In this embodiment, as shown in FIG. 5, the temperature is measured in the circumferential direction of the rolled material. In order to make the temperature measurement points evenly spaced, (considered to be proportional) is detected by the speedometer 9.

FIG. 6 shows this relationship. In Figure 6,
U is the rotational speed of the material 3, UL is the approach speed, and UR is the vertical component speed.

D is the outer diameter of the rolled material 3.

Here, as is clear from the figure, the relationship between U and UR zUL is Ua=Usinθ −
(1) UL = TJ COSθ
...(2).

Here, if the diameter of roll 1 is D p z and the backward movement rate between the roll and the material is ψ, then U=k'Np・π・Dr (1−ψ) ・・
・(3) k: Becomes a constant.

Therefore, the time fg required for the material to rotate once is: Here, if the number of times the temperature Tl is measured during one rotation of the material is n, then the sampling time ts is t S = t
B, / n −・−(
5).

Therefore, in the computer 6, first, DP, ψl D lθ which is set by the input means 6 and stored in the internal storage device
, n, etc., and the output NP of the speedometer 9, the sampling period ts is determined.

When the rolled material 3 reaches the installation position of the temperature sensor 5 (for example, at an appropriate point after being bitten by the rolling mill), the output T1 of the temperature sensor 5 is output every time period t3 determined previously.
take in.

When the number of times of acquisition reaches n times, one-time acquisition is ended.

Then, as in the previous embodiment, n temperature measurements T1
~Tn is used to detect the soaking state.

Then, the detection result is outputted to the 1,000-stage display 8.

When the rolled material 3 has entered the rolling mill to a certain extent, the output T1 of the temperature detector 5 is taken in again at a period of ts, and the soaking state is similarly detected.

In other words, the soaking state of the rolled material in the circumferential direction is repeatedly detected multiple times in the longitudinal direction of the rolled material.

In this way, not only can the accurate soaking state of the rolled material be determined, but also this soaking state can be used as a useful parameter when controlling a furnace, rolling mill, etc.

In the example shown in Fig. 4, the rolled material is rotated in the rolling mill, so this was used. However, in a rolling mill that does not rotate the rolled material, the soaking state by one temperature sensor cannot be maintained. In this case, at a suitable location while the rolled material is extracted from the furnace and transported to the rolling mill,
The same can be achieved by providing a temperature detector and equipment that applies rotation to the rolled material.

Furthermore, without rotating the rolled material, the temperature detector may be moved in the circumferential direction of the rolled material and the temperature detected at each time may be utilized.

Even if there is only one temperature detector, it is possible to detect the uniform heating state in the circumferential direction of the rolled material.
It will be clear from the above description that it can also be realized by using more than one temperature detector.

The thermal soak state detected in this way provides useful data for the operator and achieves stable operation, but
By using this soaking state, it is possible to improve the degree of soaking, that is, the degree of uniformity of the rolled material.

Next, a specific method of the present invention for controlling the degree of ripeness using a soaking state will be described.

FIG. 7 is an embodiment of the present invention illustrating the method.

In the figures, the same numbers as in FIG. 2 indicate the same parts.

50 indicates a temperature detector, which corresponds to 51 to 5n in FIG.

Reference numeral 10 indicates a furnace, the details of which are shown in FIG. 8, for example.

In FIG. 8, 100 is a furnace main body, 101 is a fuel supply pipe, 102 to 106 are burners, and 112 to 116 are control valves for adjusting the fuel supplied to each burner.

Reference numeral 120 indicates a conveyor for transporting charged rolled material, and serves as a preheating zone and a heating zone.

130 is a conveyor for extracting the rolled material that has reached the soaking zone from the furnace to the outside.

121 and 122 are motors that drive the conveyor 120;
131 and 132 are motors that drive the conveyor 130.

140 shown in FIGS. 7 and 8 is a furnace control device that controls the control valves 112 to 116 and motors 121, 122, 131, and 132 in accordance with signals output from the computer 6.

In the configuration shown in FIG. 7, the rolled material 3 that has been preheated, heated, and soaked is extracted from the furnace 10.

The circumferential temperature of each rolled material 3 that has been extracted is detected by the temperature detector 50 one by one.

This detected value Tl-Tn is taken into the computer 6, where the soaking state of the rolled material is detected.

Various specific methods can be considered, but in this example, the soaking state is recognized based on the difference ΔTM between the maximum value TMAX and the minimum value TMIN of the detected values.

The specific method of recognizing the soaking state by ΔTM is clear from FIGS. 2 and 3 and the above-mentioned explanations thereof, and will therefore be omitted here.

Next, using the soaking state ΔTM stored in the post-calculation storage device 63, the computer 6 uses the soaking state ΔTM of the furnace 10 in the soaking zone of the furnace 10 if the soaking is worse than the preset standard ΔTo. Adjust the speed.

That is, by multiplying ΔTM by a certain coefficient G, the speed setting correction amount Δ is sent to the furnace control device 140 via the process input/output device 61.
Output SK.

ΔSK=G・ΔTM...(6
) where G is a coefficient whose value is determined by the furnace process.

In some cases, it may be determined by repeating trial and error using a synthesis method.

The reactor control device 140 incorporating ΔSK makes speed corrections for the motors 131 and 132 commensurate with this amount of correction.

Of course, as the speeds of the motors 131 and 132 are corrected, the preheating zone and the heating zone are also affected, so when ΔSK is larger than a certain value, the motors 1 21 , 1
It is preferable that the speed correction in 22 also be performed in accordance with ΔSK.

The speed correction amounts of the motors 121 and 122 may be output from the computer 6 separately from ΔSK, or may be output from the furnace control device 140.
It is also possible to calculate based on ΔSK and adjust based on it.

In this way, by correcting the motor speed in the soaking zone based on the soaking state ΔTM, it is possible to adjust the time in which the rolled material is in the furnace, thereby making it possible to improve the soaking state.

Adjustment of the uniform heat state can be easily achieved by adjusting the speed of the motor, but it is not limited to this, and the inside of the furnace can be adjusted by adjusting the amount of fuel, adjusting the burner injection angle, adjusting the length of the burner frame, etc. This can also be achieved by adjusting the thermal energy distribution.

Such adjustment of the thermal energy distribution is achieved by repeatedly detecting the soaking state in the circumferential direction of the rolled material several times in the longitudinal direction of the rolled material.
By using these values, it is possible to achieve this with high accuracy.

In addition, in the above example, the furnace 10 is adjusted by detecting the soaking state of each rolled material, but in practice, the soaking state of the past m rolls (m is any natural number of 2 or more) is stored. Therefore, it is preferable to adjust the furnace 10 using these values because stable control can be achieved.

In this case, the average value of the soaking conditions for the past m processes may be used, but considering that the state of the furnace process changes over time, the soaking conditions for m processes should be equally applied to the control. I cannot say that it is preferable.

Therefore, values obtained by multiplying each of the past m programs or the latest one and the other ones by different influence coefficients are used.

When ΔTM used in the explanation of the embodiment of FIG. 7 is used as a soaking state, the following relationship is obtained.

ΔSKj=G1・ΔTM1+G2・ΔTM2+...−
+Gm ・ΔTMm ... (7) However, ΔSKj is the control amount of the furnace 10 at the time of extraction of the jth rolled material, G1-Gm is each influence coefficient, ΔTMt~Δ
TMm indicates the soaking state for the past m runs.

Alternatively, ΔSKj=G1・ΔTM1+Gj−1. ΔsKj−,・
...(8) However, G1 is an influence coefficient for multiplying the latest soaking state ΔTMI, ΔSKj-1 is the control amount of the furnace 10 at the time of extracting the j - 1st rolled material, and Gj-1 is ΔsK-
The influence coefficient for multiplying by 1 is shown.

The control in which the most recent soaking state is given more importance (weighting) by multiplying the soaking state by the influence coefficient is not limited to equations (7) and (8) above.

In the embodiment shown in FIG. 7 described above, the soaking state is detected immediately after the rolled material 3 is extracted from the furnace, and the furnace is controlled based on the detected value. There is no problem in controlling the furnace based on the detected value using the detection method.

In this case, the rolled material is subjected to temperature-related disturbances during its transfer from the furnace exit side to the rolling mill, and in some cases it is preferable to compensate for this (for example, by using a smoothing method).

On the other hand, in a process in which it has been experimentally confirmed that the temperature-related disturbance does not change much as a function of time, it is preferable to use the soaked temperature state detection value as shown in FIG. 4 as is.

In these cases as well, it is natural that it is preferable to control the furnace based on data for the past m cycles.

Next, another embodiment will be described in which the temperature soaking control of the rolled material is performed using the detected value of the heat soaking state.

FIG. 9 shows another embodiment of the invention.

In the figure, the same numbers as in FIG. 7 indicate the same parts.

Reference numeral 20 indicates equipment for adjusting the uniform heating state of the rolled material 3. Specifically, electrodes are installed in the circumferential direction of the rolled material, and the current is adjusted at each electrode to control the generation of Joule heat in the circumferential direction. Alternatively, it is a cooling device that installs cooling water nozzles in the circumferential direction of the rolled material and controls the temperature distribution in the circumferential direction of the rolled material by adjusting the flow rate and pressure of the cooling water nozzles.

Reference numeral 200 indicates a heat soaking control device that controls the equipment 20 for adjusting the heat soaking state.

300 indicated by a broken line indicates a rolling mill control device that controls the rotation speed, opening degree, etc. of the rolling mill.

In such a configuration, the rolled material 3 extracted from the furnace 10 is
The temperature in the circumferential direction is detected by a temperature detector 50.

These detected values T1 to Tn are used to detect the soaking state in the computer 6 using the same method as described above.

If it is determined that the detected soaking state is worse than a certain reference value, the furnace 10 is controlled in the same way as in the case of FIG. 7.

However, what must be noted here is that no matter how the soaking state of the rolled material 3 extracted from the furnace is detected and the furnace 10 is controlled based on the result, the extracted rolled material 3 It is impossible to achieve good soaking conditions.

Therefore, in the embodiment shown in FIG. 9, the rolled material 3 whose soaking state has been detected is brought into a good soaking state by feedforward control.

Suppose now that when the soaking state of a certain rolled material 3 is detected, very good results are not obtained.

The computer 6 outputs a heat soaking control amount to the heat soaking control device 200 according to the stored heat soaking state.

Another thing to note here is the necessity for the computer 6 to store the detection position and detection value of the temperature detector 50.

The position of the rolled material 3 detected by a certain temperature detector,
For example, it is meaningless if the positions of the cooling nozzles do not match.

Therefore, the calculator 6 does not simply output a signal proportional to the soaking state to the control device 200, but multiplies the soaking state by a coefficient corresponding to the output T1 of each temperature detector, and outputs a signal proportional to the temperature soaking state to the control device 200. Outputs the control amount of the cooling nozzle.

Upon receiving such a control amount, the soaking control device 200 adjusts each cooling nozzle in accordance with the control amount based on the output of the billet detector 201 indicating that the rolled material 3 has arrived.

By performing such control, the rolled material extracted from the furnace can also be kept in a good soaking state.

Note that the computer 6 also outputs output to the rolling mill control device 300 (see the broken line in the figure), which is of course used to make the rolling mill control side aware of the quality of the soaking state.
This indicates that each setting value on the rolling mill side is reset using the detection result of the soaking state.

Although the control indicated by the broken line is not directly related to the soaking control, it is a necessary control in order to obtain a high-quality product.

As described above in detail, according to the present invention, it is possible to detect the uniform heating state, which is an important point in the occurrence of uneven wall thickness pipes, which is a problem in pipe manufacturing processes and the like.

In addition, since the detected soaking state can be used to control the soaking state of the furnace and other parts, stable operation can be achieved.

[Brief explanation of the drawing]

Fig. 1 is a drawing showing an example of a rolling mill for perforation, Fig. 2 is a drawing showing a specific example of detecting a soaking state, Fig. 3 is a flowchart drawing showing a specific method of detecting a soaking state, and Fig. Figures 5 and 6 are drawings showing other specific examples of soaking state detection.
The drawings are for explaining the embodiment shown in Fig. 4, Fig. 7 is a drawing showing an embodiment of soaking state control according to the present invention, Fig. 8 is a drawing showing an example of the furnace, and Fig. 9 is a drawing for explaining the embodiment shown in Fig. 4. It is a drawing which shows another Example of soaking state control by this invention. 5, 50, 51-55...temperature detector, 6...calculator,
7...Data input section, 8...Display section, 9...Speedometer, 1
0...Furnace, 140...Furnace control device, 20...Equipment for equalizing heat adjustment, 200...Soaking temperature control device 300...Rolling mill control device.

Claims (1)

[Claims] 1. Measure the temperature at a plurality of points in the circumferential direction of the rolled material extracted from the furnace, detect the soaking state based on the measured values, and detect the soaking state according to the detected soaking state. A method for controlling the uniform temperature of a rolled material, which comprises adjusting the length of time the rolled material remains in the furnace and/or the temperature in the furnace. 2. In the heating soaking control method according to claim 1, the value of the difference between the maximum value and the minimum value among the plurality of measured temperature values is taken as an index of the heating soaking state, and the index is used. A soaking time control method for a rolled material, characterized in that the length of time the rolled material stays in the furnace and/or the temperature in the front furnace is adjusted. In this step, the rolled material is rotated, and the output of one or more temperature detectors provided at the entry point of the rolled material is captured at time intervals synchronized with the rotation speed, and the captured value is used as the measured value. A method for controlling the uniform heating of a rolled material, comprising: detecting a uniform heating state, and adjusting the residence time of the rolled material in the furnace and/or the temperature in the furnace according to the detected uniform heating state. . 4. Measure the temperature at multiple points in the circumferential direction of the rod-shaped rolled material immediately after being extracted from the furnace, detect a soaking state based on the measured values, and adjust the temperature of the furnace and rolling mill according to the soaking state. 1. A method for controlling heat equalization of a rolled material, comprising controlling a heat equalizing adjustment means provided between the steps. 5. A heat soaking control method for rolled material according to claim 4, characterized in that a heat soaking adjustment section of the furnace is feedback-controlled using the heat soaking state.